Prospective audit and feedback of piperacillin-tazobactam use in a large urban tertiary care hospital

Background: Prospective audit and feedback has been shown to decrease antimicrobial exposure and costs, while improving patient outcomes. We evaluated the appropriateness of piperacillin-tazobactam orders and the cost avoidance associated with optimization. Methods: Prospective audit and feedback was performed for all adult patients receiving at least two doses of piperacillin-tazobactam in a large tertiary care facility between January 18 and February 10, 2016. When the antimicrobial regimen was assessed to be suboptimal, a recommendation was made to optimize therapy. Cost avoidance was calculated by subtracting the cost of the new regimen from the cost of the original regimen. Results: Piperacillin-tazobactam orders were considered inappropriate 38.5% of the time. Respiratory indications were appropriate in only 52.6% of cases. Intra-abdominal and skin and soft tissue indications were appropriate 82.6% and 70% of the time, respectively. The cost avoidance associated with this study was projected to be Can$28,766 per year. Conclusions: The inappropriate use of piperacillin-tazobactam was high. There would be value in antimicrobial stewardship interventions targeting its use.